/*
 * Copyright 2012-2017 Spring Initializr authors. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.baidu.formula.launcher.model;

import org.springframework.util.Assert;

/**
 * Define a {@link Version} range. A square bracket "[" or "]" denotes an inclusive
 * end of the range and a round bracket "(" or ")" denotes an exclusive end of the
 * range. A range can also be unbounded by defining a a single {@link Version}. The
 * examples below make this clear.
 *
 * <ul>
 * <li>"[1.2.0.RELEASE,1.3.0.RELEASE)" version 1.2.0 and any version after
 * this, up to, but not including, version 1.3.0.</li>
 * <li>"(2.0.0.RELEASE,3.2.0.RELEASE]" any version after 2.0.0 up to and
 * including version 3.2.0.</li>
 * <li>"1.4.5.RELEASE", version 1.4.5 and all later versions.</li>
 * </ul>
 *
 * @author Stephane Nicoll
 */
public class VersionRange {

    final Version lowerVersion;
    final boolean lowerInclusive;
    final Version higherVersion;
    final boolean higherInclusive;

    // For Jackson
    @SuppressWarnings("unused")
    private VersionRange() {
        this(null, false, null, false);
    }

    protected VersionRange(Version lowerVersion, boolean lowerInclusive,
                           Version higherVersion, boolean higherInclusive) {
        this.lowerVersion = lowerVersion;
        this.lowerInclusive = lowerInclusive;
        this.higherVersion = higherVersion;
        this.higherInclusive = higherInclusive;
    }

    public VersionRange(Version startingVersion) {
        this(startingVersion, true, null, false);
    }

    /**
     * Specify if the {@link Version} matches this range. Returns {@code true}
     * if the version is contained within this range, {@code false} otherwise.
     */
    public boolean match(Version version) {
        Assert.notNull(version, "Version must not be null");
        int lower = lowerVersion.compareTo(version);
        if (lower > 0) {
            return false;
        } else if (!lowerInclusive && lower == 0) {
            return false;
        }
        if (higherVersion != null) {
            int higher = higherVersion.compareTo(version);
            if (higher < 0) {
                return false;
            } else if (!higherInclusive && higher == 0) {
                return false;
            }
        }
        return true;
    }

    public Version getLowerVersion() {
        return lowerVersion;
    }

    public boolean isLowerInclusive() {
        return lowerInclusive;
    }

    public Version getHigherVersion() {
        return higherVersion;
    }

    public boolean isHigherInclusive() {
        return higherInclusive;
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        if (lowerVersion != null) {
            sb.append(lowerInclusive ? ">=" : ">").append(lowerVersion);
        }
        if (higherVersion != null) {
            sb.append(" and ").append(higherInclusive ? "<=" : "<").append(higherVersion);
        }
        return sb.toString();
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + (higherInclusive ? 1231 : 1237);
        result = prime * result
                + ((higherVersion == null) ? 0 : higherVersion.hashCode());
        result = prime * result + (lowerInclusive ? 1231 : 1237);
        result = prime * result + ((lowerVersion == null) ? 0 : lowerVersion.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        VersionRange other = (VersionRange) obj;
        if (higherInclusive != other.higherInclusive) {
            return false;
        }
        if (higherVersion == null) {
            if (other.higherVersion != null) {
                return false;
            }
        } else if (!higherVersion.equals(other.higherVersion)) {
            return false;
        }
        if (lowerInclusive != other.lowerInclusive) {
            return false;
        }
        if (lowerVersion == null) {
            if (other.lowerVersion != null) {
                return false;
            }
        } else if (!lowerVersion.equals(other.lowerVersion)) {
            return false;
        }
        return true;
    }

}
